<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
// $Id: DbSqlite.class.php 2729 2012-02-12 04:13:34Z liu21st $

/**
 +-------------------------------
 * Sqlite数据库驱动类
 +-------------------------------
 */
class DbSqlite extends Db {

	/**
	 +----------------------------------------------------------
	 * 架构函数 读取数据库配置信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param array $config 数据库配置数组
	 +----------------------------------------------------------
	 */
	public function __construct($config='') {
		if ( !extension_loaded('sqlite') ) {
			throw_exception(L('_NOT_SUPPERT_').':sqlite');
		}
		if(!empty($config)) {
			if(!isset($config['mode'])) {
				$config['mode']	=	0666;
			}
			$this->config	=	$config;
			if(empty($this->config['params'])) {
				$this->config['params'] =   array();
			}
		}
	}

	/**
	 +----------------------------------------------------------
	 * 连接数据库方法
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function connect($config='',$linkNum=0) {
		if ( !isset($this->linkID[$linkNum]) ) {
			if(empty($config))	$config	=	$this->config;
			$pconnect   = !empty($config['params']['persist'])? $config['params']['persist']:$this->pconnect;
			$conn = $pconnect ? 'sqlite_popen':'sqlite_open';
			$this->linkID[$linkNum] = $conn($config['database'],$config['mode']);
			if ( !$this->linkID[$linkNum]) {
				throw_exception(sqlite_error_string());
			}
			// 标记连接成功
			$this->connected	=	true;
			//注销数据库安全信息
			if(1 != C('DB_DEPLOY_TYPE')) unset($this->config);
		}
		return $this->linkID[$linkNum];
	}

	/**
	 +----------------------------------------------------------
	 * 释放查询结果
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 */
	public function free() {
		$this->queryID = null;
	}

	/**
	 +----------------------------------------------------------
	 * 执行查询 返回数据集
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  sql指令
	 +----------------------------------------------------------
	 * @return mixed
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function query($str) {
		$this->initConnect(false);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		//释放前次的查询结果
		if ( $this->queryID ) $this->free();
		N('db_query',1);
		// 记录开始执行时间
		G('queryStartTime');
		$this->queryID = sqlite_query($this->_linkID,$str);
		$this->debug();
		if ( false === $this->queryID ) {
			$this->error();
			return false;
		} else {
			$this->numRows = sqlite_num_rows($this->queryID);
			return $this->getAll();
		}
	}

	/**
	 +----------------------------------------------------------
	 * 执行语句
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  sql指令
	 +----------------------------------------------------------
	 * @return integer
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function execute($str) {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		$this->queryStr = $str;
		//释放前次的查询结果
		if ( $this->queryID ) $this->free();
		N('db_write',1);
		// 记录开始执行时间
		G('queryStartTime');
		$result	=	sqlite_exec($this->_linkID,$str);
		$this->debug();
		if ( false === $result ) {
			$this->error();
			return false;
		} else {
			$this->numRows = sqlite_changes($this->_linkID);
			$this->lastInsID = sqlite_last_insert_rowid($this->_linkID);
			return $this->numRows;
		}
	}

	/**
	 +----------------------------------------------------------
	 * 启动事务
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return void
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function startTrans() {
		$this->initConnect(true);
		if ( !$this->_linkID ) return false;
		//数据rollback 支持
		if ($this->transTimes == 0) {
			sqlite_query($this->_linkID,'BEGIN TRANSACTION');
		}
		$this->transTimes++;
		return ;
	}

	/**
	 +----------------------------------------------------------
	 * 用于非自动提交状态下面的查询提交
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function commit() {
		if ($this->transTimes > 0) {
			$result = sqlite_query($this->_linkID,'COMMIT TRANSACTION');
			if(!$result){
				throw_exception($this->error());
			}
			$this->transTimes = 0;
		}
		return true;
	}

	/**
	 +----------------------------------------------------------
	 * 事务回滚
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return boolen
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	public function rollback() {
		if ($this->transTimes > 0) {
			$result = sqlite_query($this->_linkID,'ROLLBACK TRANSACTION');
			if(!$result){
				throw_exception($this->error());
			}
			$this->transTimes = 0;
		}
		return true;
	}

	/**
	 +----------------------------------------------------------
	 * 获得所有的查询数据
	 +----------------------------------------------------------
	 * @access private
	 +----------------------------------------------------------
	 * @return array
	 +----------------------------------------------------------
	 * @throws ThinkExecption
	 +----------------------------------------------------------
	 */
	private function getAll() {
		//返回数据集
		$result = array();
		if($this->numRows >0) {
			for($i=0;$i<$this->numRows ;$i++ ){
				// 返回数组集
				$result[$i] = sqlite_fetch_array($this->queryID,SQLITE_ASSOC);
			}
			sqlite_seek($this->queryID,0);
		}
		return $result;
	}

	/**
	 +----------------------------------------------------------
	 * 取得数据表的字段信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return array
	 +----------------------------------------------------------
	 */
	public function getFields($tableName) {
		$result =   $this->query('PRAGMA table_info( '.$tableName.' )');
		$info   =   array();
		if($result){
			foreach ($result as $key => $val) {
				$info[$val['Field']] = array(
                    'name'    => $val['Field'],
                    'type'    => $val['Type'],
                    'notnull' => (bool) ($val['Null'] === ''), // not null is empty, null is yes
                    'default' => $val['Default'],
                    'primary' => (strtolower($val['Key']) == 'pri'),
                    'autoinc' => (strtolower($val['Extra']) == 'auto_increment'),
				);
			}
		}
		return $info;
	}

	/**
	 +----------------------------------------------------------
	 * 取得数据库的表信息
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return array
	 +----------------------------------------------------------
	 */
	public function getTables($dbName='') {
		$result =   $this->query("SELECT name FROM sqlite_master WHERE type='table' "
		. "UNION ALL SELECT name FROM sqlite_temp_master "
		. "WHERE type='table' ORDER BY name");
		$info   =   array();
		foreach ($result as $key => $val) {
			$info[$key] = current($val);
		}
		return $info;
	}

	/**
	 +----------------------------------------------------------
	 * 关闭数据库
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 */
	public function close() {
		if ($this->_linkID){
			sqlite_close($this->_linkID);
		}
		$this->_linkID = null;
	}

	/**
	 +----------------------------------------------------------
	 * 数据库错误信息
	 * 并显示当前的SQL语句
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	public function error() {
		$this->error = sqlite_error_string(sqlite_last_error($this->_linkID));
		if($this->debug && '' != $this->queryStr){
			$this->error .= "\n [ SQL语句 ] : ".$this->queryStr;
		}
		return $this->error;
	}

	/**
	 +----------------------------------------------------------
	 * SQL指令安全过滤
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @param string $str  SQL指令
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	public function escapeString($str) {
		return sqlite_escape_string($str);
	}

	/**
	 +----------------------------------------------------------
	 * limit
	 +----------------------------------------------------------
	 * @access public
	 +----------------------------------------------------------
	 * @return string
	 +----------------------------------------------------------
	 */
	public function parseLimit($limit) {
		$limitStr    = '';
		if(!empty($limit)) {
			$limit  =   explode(',',$limit);
			if(count($limit)>1) {
				$limitStr .= ' LIMIT '.$limit[1].' OFFSET '.$limit[0].' ';
			}else{
				$limitStr .= ' LIMIT '.$limit[0].' ';
			}
		}
		return $limitStr;
	}

}